Filter



NOV. 24, 1953 E, PQLACCQ 2,660,167

FILTERA Filed May 27, 1952 E'rxeNN; PoLAcco -l NVE'NTOR Patented Nov. 24, v1.953

i UNITED stares assalti raar orties 9 Claims. i

The present invention has for its object to provide an improved iilter for liquids injectable in human and animal bodies through the veins or otherwise, and in particular for injection of blood, plasma and lysats (liquids from the maceration of albuminoug organsr and others), in the course of blood transfusions and the like.

The invention has more particularly for its object to provide a lter for such injectable lquids of very simple construction composed of a small number of separable elements that yfacili-- tates sterilization and inspection of vtheir surfaces and may be assembled in a thoroughly fluid-tight manner and separated almost instantaneously in the course of an injecting operation, thereby permitting immediate precautions to be taken in case of emergency.

Other advantages and features of the invention will be apparent from the ensuing description.

In the accompanying drawing: y Fig. i shows an exploded view of the component parts of the filter in accordance with the invention.

Fig. 2 is a longitudinal section of the assembled lter provided with a rllter plug.

Fig. 3. shows, by Way of example, the filter employed with a blood transfusion apparatus.

In the illustrated embodiment, the filter is composed of three principal parts A, B and C adapted to be fitted together and maintained assembled by rings D of rubber or like material or by springs.

The three pieces A., B and C are coaxial bodies of revolution and are open from end to end along their axis. All three may be made from a transparent material such as glass or any other strong synthetic substance immune from attack by the substances to iilter or porcelain or any other material that is transparent, translucid or even opaque. l

The material used may or may not be the same for the three pieces.

The piece A. constitutes a connection piece for the'supply of the fluid to lter. At its top end it is provided with a nozzle I and the latter is followed by a cylindrical portion 2 that is enf larged atv 3 into a frustofconical connection portion whose diameter decreases down to the open end 4. The outer frusto-conical surface of the connection portion 3 is perfectly smooth. This smooth surface may be obtained by means of the operation commonly termed lapping in which the surface of the work is improved by the grinding action of loose abrasive.

. Two radial arms 6 are welded at 5 to the cylinm (Cl. 12S-214) drical portion 2, these arms being terminated at 'i by portions slightly raised in the shape of hooks.

The intermediate or central piece B constitutes a iilter chamber and comprisesfrom top to bottom in coaxial superposed relationship:

(a) A downwardly tapered frusto-conical connection portion t reinforced at its top rim by a lip the inner surface Il) of this portion 8 being perfectly smooth, for example lapped. The taper of the inner surface I0 is exactly the same as that of the outer surface of the tapered connection portion 3 of the part A of the filter so that the portion 8 may lit in a completely duid-tight way on the connection 3.

(b) A portion I I of frusto-conical or like shape downwardly iiared.

(c) A connection portion I2 also ffrusto-conical downwardly tapered the outer surface o f which is frusto-conical and exactly smooth, for example lapped.

(d) An end portion I3 forming a conical funnel downwardly tapered and provided with a lower aperture It of small bore (of about one to two millimetres diameter) As can be seen, these three portions II, I2 and I3 form a lter chamber I5.

Finally, the connection end piece C (or flow reservoir) has a substantially very elongated conical shape and includes an upwardly flared irustomconical upper connection portion I6 the upper rim of which is provided with an outer reinforcing lip il. Y The inner surface of said portion IE is exactly conical and smooth, for example lapped, its taper being exactly equal to that of the outer surface of the portion I 2 of the piece B, thereby permitting a highly fluid-tight assem bly of these two pieces B and C.

Below the portion l t, the part C is downwardly iiared at I8 over a short length and then is extended by a long downwardly tapered portion I9 of frusto-conical or like shape terminated at its small end by a connection nozzle 20. This part C includes adjacent the largest part of the coni-` cal portion I9, two external radial arms 2l, at-

tached by welding at 21a and curved towards the connection nozzle 2li so as to form two hooks.

Fig. 2 shows the lter assembled. In the cham# ber I5 is lodged a well-rammed plug of gauze 22. The part A is then hermetically tted into the part B and the latter is then hermetcally fitted into the part C. Preferably, the connection portions are slightly greased before assembly with a very thin nlm-of petroleum jelly or paraiiin` oil. The assembly is elastically held together by 3 elastic means comprising two removable rings D that are stretched between the arms 6 and 2! brought in line in the course of assembly.

The lter is then ready for use. The liquid to be ltered is then admitted in the direction of the arrow f1 (Fig. 2) through the nozzle of the part A and the products to be filtered oir are retained by the plug 22 through which the liquid passes. It will be noticed that this plug when soaked with the liquid adapts itself very closely to the frustoconical portions l2 and i3 of the part B of the filter and thereby ensures aV perfect filtration without risk of the liquid flowing between the plug 22 and the inner surface of the part B of the filter.

The ltered liquid passes, drop by drop; through the aperture I4 and ows in the direction of arrow f2 through the outlet nozzle 20.

Fig. 3 illustrates an application of the filter to a blood transfusion operation. The liquid 23, to

be injected after it has been filtered, is contained in a'vessel or flask 2liat a level higher than the lter. 'I'he lower connection of this vessel is connected by a exible tube 25 of rubber or like flexible and elastic material to the nozzle l of 2.8-, opens out into the exterior through its upper end 29v and into the vessel through a hollow needle 29a.

Lastly, the discharge nozzle 20 of the piece C isconnected'by a` exible and elastic tube 30 to the injection needle 3|.

The liquid -2-3 iowsfthereforaY through the filter and passes drop by drop, through the aperture I4 ofgthe part Band collects in its bottom part @where the level rises'if, the flow through the needle 3 t is-less than the now into the iilter. The input flow is regulated so as to maintain in thegpart C a substantiallyI constant reserve of filtered liquid.;-

The :filter in accordance Vwith theinvention has the following principalv advantages:

(ai It` is very easily cleaned, washed and sterilized, owing to its being composed of, preferably, a transparent material, which makes it very easyv to observe the state' of thev surfaces. Moreovenowing tothe.- fact that it can be taken apart, these' surfaces are veryv easy to get at'.

(bf): The liquid is filtered through a plug (wick or'compressl packed at 22- Hence, since the filter may be taken apart,` if theA lter becomes clogged the intermediate parti B may be easily replaced-j by an' identical part containing" a new plugor the used plug may be removed with sterilized tweezers and replaced by another sterilizedeplug.

(c) Owingy to thel'very long shape of the piece C? there; is* little likelihood of this piece becoming clioked up." I-iowever,` if'A such a choking ofthe part C? happens to cause a rise in the liquid level up-rto the aperture l'iif of said part B, afterV having stoppedi the. supply of liquid through the tube 25,.-by: means of the'v tap 2S', it is possible, by slightly; separating the parts Bi and C, to l'et a l-ittle'air in-'the part C over-the liquid' it contains, and: the liquid level in this partV C rapidly drops. The two parts B-f andi C are then very easily ittedv together without further dismounting the filter.'

(d)t In the eventofa quantity of airentering the, 'supply tube 2-5 for 'any reasonl (during the exchangefof the-flask` 2-4, for example) itis-possible, byclamping theoutlet tube-z 35iV and sepa- 4 rating the two parts B and C, to let the air through the aperture I4. As soon as the liquid arrives, the part C is filled up to a suitable level, the parts B and C are tted together, the clamp is removed from the tube 30, and the transfusion resumed Without danger.

(e) The flow may be either rapid or slow without this adversely affecting the ltration.

The invention is not limited to the details of construction described and illustrated in the accompanying drawing, which have been given solely by way of example.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

l. In a filter for liquids injectable in human and animal bodies,` said filter being adapted to be interposed between a supply pipe of 'the liquid to be filtered and a discharge pipe for the filtered liquid, in combination: a central piece of revolution'and open from end to end along its axis and adapted to contain a removable nlter plug, two connection pieces that are also bodies of revolution and openfrorn end to end along their axes'ancl are adapted to connect said central piece respectively to said supply pipe for the liquid to be iiltered and to' said discharge pipe of the filtered liquid, the three pieces 'being provided with interiitting frusto-conical smooth connection portions concentric'with said axes, said connection pieces being respectively in intertting engagement with said central piece at either end thereof by means of said connection portions and at least one elastic device for elastically holding together these pieces in interfitting engagement at their connection portions in a hermetically sealed dismoun-table' coaxial as'- se'n'ib'ly.`

2. Filter as claimedz in claim 1, in which said three pieces are of a transparent= material.

3. Filter as claimed in claim l, inwhich said three pieces are of a translucid material.

4. Filter as claimed in claim l, in which said connection portions have a lapped surface.

5. In a filter for a liquid injectable in human or animal bodies, said lter being adapted to be interposed between a` supply pipe for the liquid to be ltered, and a discharge pipe for the ltered liquid, in combination; a rst connection piece of revolution about an axis and open from end to end along said axis' and provided at one of its ends with a nozzle for its fluid-tight connectionv to said supply pipe and at its other end with a smooth frusto-conical male portion; an in.- termediate ,piece also Vof revolution about its axisV and forming a lter chamber that is open at one end of said intermediate piece through a smooth. frusto-conical aperture vcomplementaryto said frusto-conical male portion and atv the other end of said intermediate piece through a hole of small'bore that allows' a drop by drop discharge of. theltered liquid', a portion of the outer surface of saidy intermediate piece adjacent y smooth female frusto-conical portion of said second connection piece being respectively in intertting engagement with said smooth frustoconical aperture and said smooth frusto-conical portion of said outer surface of said intermediate piece; and elastic devices for elastically holding together said two connection pieces and said intermediate piece in intertting engagement at said smooth frusto-conical portions in a hermetically sealed dismountable coaxial assembly, said elastic means being connected to each of said connection pieces.

6. Filter as claimed in claim 5, in which said two connection pieces are provided externally with a similar number of radially extended arms forming hooks, said elastic devices consisting of as many elastic rings as there are radially extended arms on each connection piece for the elastic holding together of the dismountable assembly, each one of said rings being connected to one oi the arms of one of said connection pieces and to one of the arms of the other connection piece.

7. Filter as claimed in claim 6 in which there are provided two elastic rings and, on each connection piece, two external arms diametrically opposite.

8. Filter for liquids injectable in human and animal bodies and adapted to be interposed between a supply pipe for the liquid to be filtered and a discharge pipe for the filteredliquid, said lter being composed of the combination of a central piece of revolution open from end to end along its axis, a lter plug housed in said central piece, two connection pieces also 'of revolution about their axes and open from end to end j device for relastically holding together these pieces in intertting engagement at said connection portions in a hermetically sealed dismountable coaxial assembly, said elastic device being attached to each of said connection pieces.

9. Filter installation for liquids injectable in human and animal bodies, this installation comprising in combination: a vessel with a head of the liquid to be filtered and provided with a lower discharge aperture; a rst exible and elastic tube connected to said aperture; a lter including a central piece of revolution open from end to end along its axis which is vertical, a filter plug housed in this central piece, a rst connection piece also of revolution and open from end to end for connecting the upper end of said central piece to said rst tube, a second connection piece also of revolution open from end to end and connected to the lower end of said central piece, said three pieces being provided with intertting frusto-conical smooth connection portions concentric with said axes, said connection pieces being respectively in interfitting engagement with said central piece at either end thereof by means of said connection portions, and elastic devices for elastically holding together these pieces in interiitting engagement at said connection portions in a hermetically sealed dismountable coaxial assembly, said elastic devices being connected to each of said connection pieces; a second flexible and elastic tube for the discharge of the ltered liquid connected at one of its ends to the lower end of said second connection piece; and an injection member connected at the other end of said second discharge pipe.

ETIENNE POLACCO.

References Cited in the file of this patent UNITED STATES PATENTS 

